RESULTS: It was found that the electric field, depending on the applied voltage, its duration and the polarization of the maize seedlings, stimulated or inhibited the growth of the seedling organs (root, mesocotyl and coleoptile). Moreover, it was also noticed that the gravitropic response of maize seedlings was inhibited at all voltages studied. Simultaneous measurements of growth and external medium pH show that auxin(IAA, indole-3-acetic acid)- and fusicoccin(FC)-induced elongation growth and proton extrusion of maize coleoptile segments were significantly inhibited at higher voltages. The ionic current flowing through the single coleoptile segment during voltage application was 1.7-fold lower in segments treated with cation channel blocker tetraethylammonium chloride (TEA-Cl) and 1.4-fold higher with IAA compared to the control. The electrophysiological experiments show that the electric field caused the depolarization of the membrane potential of parenchymal coleoptile cells, which was not reversible over 120 min.
CONCLUSIONS: It is suggested that a DC electric field inhibits the plasma membrane H+ pump activity and K+ uptake through voltage-dependent, inwardly rectifying ZMK1 channels (Zea mays K+ channel 1). The data presented here are discussed, taking into account the \"acid growth hypothesis\" of the auxin action and the mechanism of gravitropic response induction.
结果:发现电场,根据施加的电压,它的持续时间和玉米幼苗的两极分化,刺激或抑制幼苗器官的生长(根,中胚轴和胚芽鞘)。此外,还注意到,在所有研究的电压下,玉米幼苗的重力响应都受到抑制。生长和外部培养基pH值的同时测量表明,生长素(IAA,吲哚-3-乙酸)-和融合霉素(FC)诱导的玉米胚芽鞘段的伸长生长和质子挤出在较高电压下显着抑制。与对照相比,用阳离子通道阻断剂四乙基氯化铵(TEA-Cl)处理的片段在施加电压期间流过单个胚芽鞘段的离子电流低1.7倍,而IAA高1.4倍。电生理实验表明,电场引起实质胚芽鞘细胞膜电位的去极化,在120分钟内是不可逆的。
结论:建议直流电场通过电压依赖性抑制质膜H泵活性和K吸收,向内整流ZMK1通道(ZeamaysK+通道1)。这里提供的数据进行了讨论,考虑到生长素作用的“酸生长假说”和重力响应诱导机制。